000 FXUS62 KTBW 090835 AFDTBW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL 335 AM EST MON NOV 9 2009 .SHORT TERM (TODAY THROUGH WEDNESDAY)...BREEZY CONDITIONS WILL CONTINUE OVER THE AREA TODAY AS THE GRADIENT BETWEEN THE SFC HIGH PRESSURE OVER THE AREA AND HURRICANE IDA TIGHTEN. CURRENTLY...IDA IS WELL WEST OF THE PENINSULA AS IT MOVES NORTH THROUGH THE CENTRAL GOMEX. THE OFFICIAL NHC FORECAST HAS IDA WEAKENING BEFORE MAKING LANDFALL AS A WEAK HURRICANE NEAR THE FL/AL BORDER AND QUICKLY TRANSITIONING TO AN EXTRATROPICAL CYCLONE. WHILE IDA WILL NOT DIRECTLY AFFECT OUR INLAND CWA AS IT DRIFTS NORTH...WINDS WILL REMAIN STRONG ENOUGH FROM TAMPA BAY SOUTHWARD FOR A LAKE WIND ADVISORY. AS LATER GUIDANCE MAKES IT WAY IN...THE LAKE WIND ADVISORY MAY NEED TO BE EXTEND FOR THE ENTIRE CWA DEPENDING THE MEAN MIXING LAYER WINDS. BY TUESDAY...WHAT REMAINS OF IDA'S CIRCULATION BEGINS BE ABSORBED WITH A MID LEVEL TROUGH DRIFTING EASTWARD. GUIDANCE IS CONSISTENT WITH IDA MERGING WITH A BAROCLINIC SYSTEM MOVING INTO THE CAROLINAS. A COLD FRONT IS EXPECTED TO DEVELOP AFTER THE MERGER OF THE SYSTEMS AND BEGIN TO SLIDE INTO OUR REGION BY TUES AFTERNOON. HAVE MAINTAINED NUMEROUS SHOWERS AND THUNDERSTORMS IN THE TUES AFTERNOON FORECAST FOR THE COASTAL WATERS AND FROM TAMPA BAY NORTHWARD. FORECASTED THERMODYNAMICS ALONG AND AHEAD OF THE FRONT ARE NOT ENTIRELY IMPRESSIVE BUT ENOUGH VORTICITY AND LL SHEAR PRODUCED FROM IDA WILL ALLOW A POTENTIAL FOR SOME STRONG STORMS AND POSSIBLE ISOLATED TORNADOES. ON WEDNESDAY...THE FRONT WILL CONTINUE TO PUSH THROUGH THE REGION AND OUT OF OUR CWA BY WED AFTERNOON. BUMPED POPS UP TO 60% FROM CITRUS SOUTHWARD IN THE OVERNIGHT HOURS AND GRADUALLY DECREASED RAINFALL CHANCES BY THE AFTERNOON. KEPT TEMPS NEAR GFS GUIDANCE BUT BUMPED THEM UP A DEGREE OR TWO IN THE OVERNIGHT HOURS TO ACCOUNT FOR CLOUD COVER. .LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)...THE EXTENDED FORECAST PERIOD IS GOING TO BE RATHER UNEVENTFUL COMPARED TO THE ONGOING SHORT TERM FORECAST. THE REMNANTS OF IDA WILL INTERACT WITH A NORTHERN STREAM TROUGH MOVING INTO THE GREAT LAKES BY 00Z THURSDAY. THE TWO FEATURES WILL MERGE...AND A DEEP H5 CUTOFF CYCLONE WILL DEVELOP AND SLIDE SOUTHEAST OFF THE MIDATLANIC COAST AND CARVE A LARGE TROUGH ACROSS THE SOUTHWESTERN ATLANTIC BY THIS WEEKEND. AT THE SAME TIME...A FAIRLY SIGNIFICANT LONGWAVE TROUGH WILL TAKE SHAPE ACROSS THE WESTERN STATES...CAUSING AN INCREASE IN RIDGING OVER THE GULF REGION. SO FLORIDA WILL REMAIN SANDWICHED IN BETWEEN THE H5 LOW OVER THE ATLANTIC AND THE RIDGE OVER THE GULF. WHILE THIS IS THE GENERAL PATTERN AND THE ECMWF AND GFS AGREE...THERE REMAIN SOME DIFFERENCES ON THE EXACT POSITIONS OF THE LOW. THE SURFACE WEATHER FEATURES WILL BE GENERALLY WEAK DURING THE PERIOD IN THE WAKE OF IDA. HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN CONUS BY FRIDAY AND THIS COMBINED WITH THE LARGE LOW OVER THE ATLANTIC WILL CREATE A DEEP NORTHERLY FLOW OF COOLER AND DRIER AIR INTO FLORIDA. EXTENDED GUIDANCE ON TODAYS 00Z RUN IS QUITE A BIT COOLER THAN THE PREVIOUS SET OF 00Z GUIDANCE. DID NOT GO AS COOL FOR NOW...BUT TRENDED COOLER THAN THE PREVIOUS FORECAST. NO RAIN CHANCES THROUGH THE EXTENDED PERIOD AS HIGH PRESSURE BUILDS BACK IN. && .AVIATION...THE MAIN AVIATION ISSUE THIS PACKAGE WILL BE WINDS. UPPER AIR INFORMATION INDICATES THAT WINDS AT 1-2KFT ARE 40-45 KTS AND THUS HAVE INCLUDED MENTION OF LLWS AT ALL SITES THRU 12-15Z. AFTER THIS TIME...THE SFC WINDS WILL BEGIN TO INCREASE. WINDS SHOULD BECOME SUSTAINED AT 15-20 KTS WITH GUSTS AS HIGH AS 25-30KTS. STRONGEST WINDS WILL BE FOUND AT SRQ...FMY...AND RSW. AS THE HURRICANE LIFTS THROUGH THE GULF...WINDS SHOULD STAY UP AFTER 02Z BUT DIMINISH SLIGHTLY OFF THEIR AFTERNOON VALUES. SKY COVER IS EXPECTED TO REMAIN VFR. A FEW SHOWERS ARE POSSIBLE THIS AFTERNOON BUT COVERAGE SHOULD BE TOO ISOLATED TO MENTION. && .MARINE...GALE WARNING IN EFFECT FOR THE OFF SHORE WATERS THROUGH THIS EVENING WITH A SMALL CRAFT ADVISORY OUT THROUGH TUESDAY AFTERNOON AS IDA MOVES TOWARDS THE NORTHERN GULF COAST. CURRENTLY IDA IS IN THE CENTRAL GULF WEST OF THE TIP OF FL. CONDITIONS ARE CONTINUING TO DETERIORATE IN OUR OFF SHORE ZONES. BUOY DATA JUST WEST OF OUR WATERS IS INDICATING WINDS GUSTING TO 30 KNOTS WITH WAVE HEIGHTS OF 8-12 FT THIS MORNING. WINDS WILL CONTINUE TO INCREASE THROUGHOUT THE DAY WITH WAVES INCREASING TO NEAR 10 FT FOR OUR OFF SHORE WATERS. FURTHER INLAND...SCA CONDITIONS WILL PERSIST THROUGH TUESDAY AS THE SFC PRESSURE GRADIENTS REMAINS TIGHT. WINDS OVER TAMPA BAY DECREASED TO LESS THAN 20 KT BUT A SMALL CRAFT EXERCISE CAUTION WILL BE WORDED IN THE CWF. && .FIRE WEATHER...RH VALUES WILL REMAIN WELL ABOVE CRITICAL THRESHOLDS. ONLY CONCERN WILL BE THE STRONG 20FT AND TRANSPORT WINDS WHICH WILL CREATE HIGH DISPERSION VALUES. && .PRELIMINARY POINT TEMPS/POPS... TPA 84 72 80 70 / 20 30 60 60 FMY 85 72 82 70 / 20 30 50 60 GIF 84 70 80 68 / 20 30 50 60 SRQ 83 73 81 70 / 20 30 50 60 BKV 83 69 79 65 / 20 30 60 60 SPG 83 73 79 71 / 20 30 60 60 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...LAKE WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM EST THIS EVENING FOR CHARLOTTE-DE SOTO-HARDEE-HIGHLANDS-HILLSBOROUGH- LEE-MANATEE-PINELLAS-POLK-SARASOTA. GULF WATERS...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 5 PM EST TUESDAY FOR BONITA BEACH TO ENGLEWOOD OUT 20 TO 60 NM-ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR BONITA BEACH TO ENGLEWOOD OUT 20 TO 60 NM-ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 5 PM EST TUESDAY FOR BONITA BEACH TO ENGLEWOOD OUT 20 NM-ENGLEWOOD TO TARPON SPRINGS OUT 20 NM- TARPON SPRINGS TO SUWANNEE RIVER OUT 20 NM. && $$ SHORT TERM/MARINE/FIRE WEATHER...20/BARRON LONG TERM/AVIATION...35/JOHNSON